We have a public mailing-list that you can e-mail at numba-users@continuum.io.
If you have any questions about contributing to Numba, it is ok to ask them
on this mailing-list. You can subscribe and read the archives on
Google Groups,
and there is also a Gmane mirror
allowing NNTP access.

If you want to contribute, we recommend you fork our Github repository, then create a branch representing
your work. When your work is ready, you should submit it as a pull
request from the Github interface.

If you want, you can submit a pull request even when you haven’t finished
working. This can be useful to gather feedback, or to stress your changes
against the continuous integration platorm. In this
case, please prepend [WIP] to your pull request’s title.

Numba has a number of dependencies (mostly Numpy
and llvmlite) with non-trivial build
instructions. Unless you want to build those dependencies yourself, we
recommend you use Conda to
create a dedicated development environment and install precompiled versions
of those dependencies there.

First add the Binstar numba channel so as to get development builds of
the llvmlite library:

Numba is validated using a test suite comprised of various kind of tests
(unit tests, functional tests). The test suite is written using the
standard unittest framework.

The tests can be executed via python-mnumba.runtests. If you are
running Numba from a source checkout, you can type ./runtests.py
as a shortcut. Various options are supported to influence test running
and reporting. Pass -h or --help to get a glimpse at those options.
Examples:

The repository’s master branch is expected to be stable at all times.
This translates into the fact that the test suite passes without errors
on all supported platforms (see below). This also means that a pull request
also needs to pass the test suite before it is merged in.

Numba is to be kept compatible with Python 2.7, 3.4 and 3.5 under
at least Linux, OS X and Windows. Also, Numpy versions 1.7 and upwards
are supported.

We don’t expect invidual contributors to test those combinations
themselves! Instead, we have a continuous integration platform. Part of
the platform is hosted at Travis-CI.
Each time you submit a pull request, a corresponding build will be started
at Travis-CI and check that Numba builds and tests without any errors.
You can expect this to take less than 20 minutes.

Some platforms (such as Windows) cannot be hosted by Travis-CI, and the
Numba team has therefore access to a separate platform provided by
Continuum, our sponsor. We hope parts of that
infrastructure can be made public in the future.